mastra-ai/mastra · error

App creation failed: ${errorDetails}

Error message

App creation failed: ${errorDetails}

What it means

createApp calls Slack's app-creation endpoint and expects ok:true. When ok is false the client builds an errorDetails string from data.error, plus per-field validation errors (data.errors with pointer/message) and response_metadata.messages, and throws with them.

Source

Thrown at channels/slack/src/client.ts:148

      app_id?: string;
      credentials?: {
        client_id: string;
        client_secret: string;
        signing_secret: string;
      };
      oauth_authorize_url?: string;
    };

    if (!data.ok) {
      // Slack may include detailed error info
      let errorDetails = data.error ?? 'unknown_error';
      if (data.errors?.length) {
        errorDetails += ': ' + data.errors.map(e => `${e.pointer}: ${e.message}`).join(', ');
      }
      if (data.response_metadata?.messages?.length) {
        errorDetails += ' - ' + data.response_metadata.messages.join(', ');
      }
      throw new Error(`App creation failed: ${errorDetails}`);
    }

    if (!data.app_id || !data.credentials || !data.oauth_authorize_url) {
      throw new Error('App creation returned incomplete data');
    }

    return {
      appId: data.app_id,
      clientId: data.credentials.client_id,
      clientSecret: data.credentials.client_secret,
      signingSecret: data.credentials.signing_secret,
      oauthAuthorizeUrl: data.oauth_authorize_url,
    };
  }

  /**
   * Delete a Slack app.
   */

View on GitHub (pinned to 75dd419e61)

Solutions

1. Read errorDetails in the message — it names the failing manifest fields (pointer) and Slack's messages; fix those fields in your SlackAppManifest
2. Verify your app configuration token is valid and has permission to create apps
3. Validate the manifest against Slack's manifest schema/docs before calling createApp

Example fix

// before
manifest.oauth_config = { redirect_urls: ['http://localhost/callback'] }; // http not allowed
// after
manifest.oauth_config = { redirect_urls: ['https://myapp.example.com/callback'] };

function validateManifest(m: SlackAppManifest): string[] {
  const errs: string[] = [];
  if (!m.display_information?.name) errs.push('display_information.name required');
  if (!m.oauth_config?.redirect_urls?.every(u => u.startsWith('https://'))) errs.push('redirect_urls must be https');
  if (!m.settings?.org_deploy_enabled && !m.settings) errs.push('settings required');
  return errs;
}
const errs = validateManifest(manifest); if (errs.length) throw new Error(errs.join(', '));

try {
  await client.createApp(manifest);
} catch (e) {
  const msg = (e as Error).message;
  if (msg.startsWith('App creation failed:')) {
    // msg contains pointer/message details — fix those manifest fields and retry
  } else throw e;
}

When it happens

Trigger: createApp() receives { ok: false } from Slack — e.g. invalid manifest, validation errors on specific manifest fields, or an auth/permission failure on the app-creation API.

Common situations: Manifest failing Slack validation (invalid icons, bad settings, missing required fields); using app config tokens without the right scopes; typo'd manifest after editing; Slack rejecting unsupported manifest features.

Related errors

• App manifest update failed: ${errorDetails}
• Token rotation failed: ${data.error}
• App deletion failed: ${data.error}
• Failed to check whether Slack app exists: ${data.error ?? 'u
• connect({ id, name }): "name" is required when connecting wi

AI-assisted analysis of mastra-ai/mastra@75dd419e61 (2026-08-30). Data as JSON: /api/errors/18fdb29162f7002f. Report an issue: GitHub.